Automatic transfer machine tool



June 2, 1953 E. M. BOWEN AUTOMATIC TRANSFER MACHINE TOOL 14 Sheets-Sheet 1 Filed Feb. 24, 1948 NVBNTO Gav 1 -Tn. Ybowen June 2, 1953 E. M. BOWEN 2,640,254

AUTOMATIC TRANSFER MACHINE TOOL Filed Feb. 24, 1948 14 Sheets-Sheet. 2

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June 2, 1953 E. M. BOWEN 2,640,254

AUTOMATIC TRANSFER MACHINE TOOL Filed Feb. 24. 1948 14 Sheets-Sheet 7 June 2, 1953 E. M. BOWEN 2,640,254

AUTOMATIC TRANSFER MACHINE TOOL Filed Feb. 24, 1948 l4 Sheets-Sheet 8 June 2, 1953 E. M. BOWEN 2,640,254

AUTOMATIC TRANSFER MACHINE TOOL Filed Feb. 24, 1948 I 14 Sheets-Sheet 9 t VENTQM ffl-rTorawavJ 14 Sheets-Sheet l0 E. M. BOWEN AUTOMATIC TRANSFER MACHINE TOOL c T N a v N June 2, 1953 Filed Feb. 24, 1948 June 2, 1953 E. M. BOWEN AUTOMATIC TRANSFER MACHINE r001.

14 Sheets-Sheet 11 Filed Feb. 24, 1948 E. M. BOWEN AUTOMATIC TRANSFER MACHINE TOOL June 2, 1953 14 Sheets-Sheet 12 Filed Feb. 24, 1948 I 4 l llll 1 A A r June 2, 1953 E. M. BOWEN 2,640,254

AUTOMATIC TRANSFER MACHINE TOOL Filed Feb. 24, 1948 14 Sheets-Sheet l4 H7 us l FORWARD RETIQRN CflTTORNSYJ Patented June 2, 1953 UNITE-D srnrss FATE UTOMATIC TRANSFER. MACHI TOOL.

Application February 24, 1948;. Serial N 0.10523,

This inven-tion relatesto machine tool organizations of the-type in which workpieces are transferred step by step through one or more stationsatwhigzh the workpiecesare located'accurately, clamped; machined or otherwise operated-u-pon, and finally'released for continued-ad- Vance:

One object of the invention is to provide a transfer machine tool" of' the above character adaptedto handleworkpieceswhich are too small or soshaped as to preclude the useof the usual dowel ljocat'ers;

A moredetail'ed object is to provide sucha machine toolorganizati'on: in which the workpieces are located preparatory to finalmachining by separate positioning motions; in two. transverse directions andithenpfinally positioned in a third dimension;

Afurther object is an automatic transfer type ofjmachine tool which is especially adapted, for operating on elongated workpieces. preferably simultaneously on opposite ends thereof;

Still another object. is toadapt themachine tool-in anovel manner for use with workpieces drawi en A' further object is to. providein anorganiza tion ofthe above character anovelmechanisrn fordetecting the failure. of one of the machine ns stat s o oper te roperly ande therindicating such defect or. automatically disabling, the machine tool-. 1 part there f. soas t r ven bsequ nt d a e- The invention also resides in the noveland simp cons uc on o th var us eol a ols s for loca ing: an c amp n the orkpiece and inspecting the same.

Other objects andadvantages of the inven t n wil be m upar n f m th followin .deaiieozdesc oti k n n conn ct o with the co mloanyin drawing n which Figure 1" is an endelevationalview of'a machine tool organization embodying the present invention, one of the parts being shown in phanom n a chan e o o Fig. 2 is a fragmentaryplan view.

Figs. Band 4' are fragmentary sections takenrespectively alongthe lines: 3'--3and"4d;of"1iigs. 2 and3, respectively.

gs. 5,6 and-1 a e. fragm ntary s t ons taken. respect v y a onsthe. li es 5:,L 5+61and T-T oflif'is. 4.

Ir s 1 s a fragm n y section aken alon e. line 32-8 ofF'ig, 7,.

Eia. 9 is a fra mentary se ti n tak n along the: line 9,9"of Fig. 8:

5 Claims. (01.29933):

2. Figs. IO-and llaredetail sections taken respectively' along the linesl d-Ml and I-l--H of Fig. 6. Fig. 1'2is a fragmentary section takenalong theline H -t2 of Fig. 2; Fig. 13 is a plan view of-the mechanism shown in Fig. 12.

Fig. 14. is a fragmentary section taken along the line Hild' of-Fig-. 2;

Fig. 15 is a fragmentary iew of one endof the workpi'ece'with' partthereofshown insection;

Fig; 16 is a fragmentary plan view of part of the unloading end of" the machine tool organization.

Fig. I? is a fragmentary sectional View taken along theline l'l--l l-"of'Fig- 1'6;

18 and-'22 when arranged end to-end form a schematiclayout of' the main movable parts of themac'hine tool organization.

Figs. 19, 20; 2'1 and23=are detail'views of the tooling at the different stations of the machine organization.

Figs. 24and 25 whenplaced one above the other form a hydraulic circuit and electric switch diagram of'the.drillingandinspecting station part of the. machine. tool organization.

For purposes of illustration, the invention has been shown in the drawings incorporated in a machine tool organization for performing drill? ing, milling and boring operations on forked portions. or yokes 19. (Fig, 4). at' opposite ends of a tube I I,the workpieceas a wholebeing designated w. finish boredin the, parallel'arms of each yoke 10;. and the interior of theyolre is milled to form parallel surfaces l3 (Figs; 15 and'23). It is to be UIlQQI tQ QhOWBVQI', t at. the n nt on s n mitod' is.k ndlofworkp e e o h p ticular character of'the metal removing operations performed thereon, but is intended tocover all modifications. and,a 1ternative constructions and. arrangements falling within the spirit and scope of: the appended claims.

In the exemplary machine tool organization shown, workpieces are loaded successively onto a shiftable transfer member atone end ofthe lineup. of machines, are moved into a station A (Figs. 3 and18') in which the holes it are drilled; are transferred to and ins ected-in a station BIFigs. 12', 13, and 18), aretransferredtosuccessive mill ingand finish boring stations C and D (Figs, 14'

' and 22), and are finally moved into an'unloading station (Figs. loand 71) at the other end ofthe machine line. Throughouttheir progress through the successive stations, the workpieces are disosed h izontal. o it on n a n i ed" i uniformly spaced" parallel relation, being ad- Alined holes I21 are, drilled and" 3 vanced sidewise into each station. In each machine station, the workpiece is disconnected from the transfer member by moving the two relative to each other laterally of the path in which the workpiece is transferred. Then, the workpiece is first shifted to position the same in one direction and then shifted in a transverse direction. Finally, the piece is shifted in a third direction to a final operating position and thus accurately located in three dimensions in relation to the tool for machining the piece. After clamping in this final position, the machining operation is performed followed by release of the workpiece and reconnection with the transfer mechanism for advance to the next station.

At each station, the locating, holding, and machining mechanisms and their power actuators are supported on spaced upright columns 14 (Fig. 1) mounted on a bed i5 and disposed on opposite sides of the path along which the workpieces are advanced. To accommodate workpieces of different lengths, one of the columns [4 is fixed to one end of the bed l5, while the other column is adjustable along ways it between the position shown in full and in phantom in Fig. 1. Such adjustment may be effected through a screw and nut mechanism (not shown) adapted to be actuated by turning a hand crank on a shaft 11 (Fig. 1).

In the present instance, the mechanism for transferring the workpieces from station to station comprises two laterally spaced bars [8 (Figs. 3, 4, 6, l8, and 22) which extend through all of the stations across the several beds i5 and are slidable endwise in guides formed on the columns l4 so that the spacing of the bars may be adjusted along with the other parts to correspond to the length of the workpieces being operated on. As shown in Fig. 4, the bar guides are formed by blocks 19 set in the columns [4 at the drilling and unloading stations and providing guide surfaces which mate with rods 20 secured to the outer sides of the bars. Clamps 2| overlie the upper edge portions of the transfer bars.

On their inner sides, the transfer bars !8 are formed with elements adapted to interfit with the end portions of the workpieces and maintain the desired spacing of the pieces along the bars. Herein, these elements are the walls of recesses 22 spaced along the bars to correspond to the spacing of the work stations, and each is adapted to receive the extreme ends of the workpiece yokes H) as shown in phantom in Fig. 4. Thus, the recesses are slightly longer than the width of the yokes i0 and are formed with an inwardly and downwardly inclined bottom 22 which tends to shift the received workpiece into an approximately centered position.

In the present instance, the transfer bars l8 are reciprocated back and forth by a hydraulic actuator located at the unloading end of the line of machines. As shown in Figs. 16 and 22, this actuator comprise a stationary cylinder 23 and a piston 24 therein whose rod is a rack meshing with a gear on a cross shaft 25 carrying gears 26 which in turn mesh with the rack teeth on the undersides of the rods 29 secured to the transfer bars. One of the gears 26 is splined on the shaft 25.

The strokes of the transfer bars l8 as determined by the length of the cylinder 23 are equal to the longitudinal spacin of the work stations from each other so that as the bars advance, the workpieces supported in the recesse 22 thereon will be moved to the next station and there positioned for proper operation of the other mechanisms thereon. In the return or idle stroke of the transfer bar, each pair of recesses 22 will be returned to the precedin station in the line preparatory to receiving the workpieces then being operated on in these stations. In this retracted position, the bars [8 will project outwardly from the first or drilling station A, and the first pair of recesses 22 will be exposed and adapted to receive the next workpiece as the operator slides this piece sidewise into loading position along the top of the bars.

After being advanced into the machining stations A, C, and D, the workpieces are disconnected from the transfer mechanism which, in this instance, is effected by lifting the pieces vertically off from the transfer bars to a position short of their final working location. For this purpose, elevator rods 28 (Figs. 3, 4, 9, and 18) are slidable in vertical guides 29 in the columns l4 and, carry at their upper ends jaws 30 and 3| (Figs. 4 and 9) which engage the undersides of the work yokes H1 inwardly from the points of engagement of the latter by the transfer bar surfaces 22 The jaw 30 is swiveled on a pin 32 which permits rocking of the jaw longitudinally of the workpiece to permit full engagement of the fiat end of a projection 33 with both arms of the yoke l0 and also engagement of a projection 34 with the adjacent tubular portion of the workpiece (see Figs. 4 and 9).

The other jaw 3| is swiveled on pins 35 (Fig. 5) journaled in flared seats 35 so as to allow for some degree of rocking of the jaw in the plane of the swiveling axis. This allows the jaw to come into full engagement with both arms of the Work yoke 10 in spite of small variations in the angular position of one of the yokes relative to the other.

The elevator rods 28 are raised and lowered by a power actuator herein comprising a piston 31 (Figs. 6 and 18) in a cylinder 38. The piston rod (see Fig. 3) is a rack meshing with the gear 39 on a cross shaft 40 bevel geared to shafts 4| which extend through the stations A, B, C, and D. The shafts M carry pinions 42 which mesh with rack bars L3 having limited lost motion connections 44 (Fig. 4) with the rods 28 and urged upwardly relative to the rods by springs 45 (Fig. 10) seated in the racks 43 and acting on an abutment 46 on the rod 23.

In the lowered positions of the elevators 28 determined by engagement of the piston 3! with the head end of the cylinder 38, the jaws 30 and 31 are disposed below the path of sidewise advance of the workpieces as indicated by the work-' piece shown in phantom in Fig. 4. .As the rods' 28 are elevated, the workpiece at each station is lifted off the transfer bars l8 and eventually elevated into engagement with downwardly facing forked or V-shaped seats 48 (Fig. 3) in blocks 49 which serve to position both ends of the workpiece sidewise and therefore horizontally in one transverse direction. The blocks 49 are guided on the column M for vertical movement in the plane of the lower jaw lugs 34 so as to engage the top of the tubular part I l of the workpiece. The blocks 49 are urged downwardly by springs 50 (Figs. 4 and 9) so that the preliminary positioning and temporaryholding of the workpiece short of its final working position is of a yieldable character. The extent of the preliminary elevating of the workpieces is determined by en-. gagement of the piston 31 with the rod end of the cylinder 38, and, in the case of each of the.

QMORM.

5 stations-18,. B; 6;..and. D',..iS::Sl.1CI I..-IaS to; carryjthe workpiece. slightly-beyondthepoint; of initial en.- gagementwith. the V-shaped1 seatsABinthe yieldable blocks 49.

Accurate andfinal vertical positioning; of the workpiece in the drilling;. milling and boring stationsA, C, and D is effected by forcinggthe lower jaws 3t and; 3'! upwardly. bypositive action to overcomethe springs 59! and raise both endsofi the l workpiece into engagement with-horizontal downwardly facing abutments 51' as; shown in Figs. 4 and 9-. These.- abutments-are rigid; with the. columns [.4 at. points adjacent. the; yieldable blocks. 49-so as to be engageablewith the: tubular. parts III of the workpiece. Such positive clamping action is producedin the present instance; byprojecting wedges 52- (Figs, 3, 4-, and 18) trans.- verselyof the elevator rods. 2-8 through: slots .53 in. the sides thereon The wedges thus; act on follower-abutments 54' (Fig; 4-) to move the rods. 28. upwardly and independently of their main actuator as permitted by the lost motion connections 44. The wedges 52 are carriedon the-tends. of;rods.55 (see Fig. 6) of pistons 56 reciprocable in. cylinders Bil-fixed on thecolumn. I 4.

The V-blocks 49 are: utilized tohold the workpiece positively against sidewise-shifting during the machining. operations. To this end, a; shaft 59 (Figs. 7 and 8) extends across theupper end portion of each block and is journaled in the column i4 supportingthela'tter so as to turn about an axis paralleling; the surfaces of the V-shapedseat 38. Right and left-hand: screw. threads 6t formed on the. shaft. mate with nuts 6! disposed on oppositesidesof. the block and acting, when tightened against the block, to pre-- vent. raising of the latter in its guides; With the block thus clamped positively;whilerengaging. the tubular part of the workpiece. any; lateral shiftingof the workpiece; along. theflatends-of. the

jaws-.31 or the abutments 5| is prevented. The. shaft 59 is turned in opposite directions; toclamp and release; the blocks 49 by an actuator comprising a piston. 63 m0vable in. a; vertical hydraulic cylinder 64 (Fig. 7) stationarily. mounted on the. associated. column. 14. The piston-:hasa lost motion connection; 65- with a rack. bar: 66- which. meshes with a pinion 61' onthe shaft .59.

When a workpieceisthus: clamped, its ends: are. accurately located-verticallyin POSitiOIls determined by the abutments 5|. Bothforks. l thereof aresimilarly positioned angularly. bycvirbtue of engagement of their armswith: the 1ugs33. of the lower jaws Stand .3

Positioningot the workpiece inan endwise direction or transversely of the-direction of 'positioning by. the V-blocks 49,.is efiected before final: or positive vertical clamping as aboveedescribed against the abutments Such positioning is. accomplished in this instance by bifurcated. arms 68 (Figs. 4, 7, and 9) which are.disposed.ont-.- wardly beyond the ends of the work yokes-..I (land areengageable with the-ends of the yoke arms when the workpieceis positioned against the pre liminary locating stops 48. The arms. 68.. are loose on and hang downwardly from horizontal shafts 69'which are journaled in overhanging parts of the columns I for endwise movement during which the flat upper ends; of. the arms slidelalong guide surfaces (Fig. 4-) whichholdthe arms againstturning on the shafts.

Movement of the arms 68 toward each other-tocenter the workpiece in relation. to the tools for operating thereon is" efiected' in thislinstance. by screw-mechanismscomprising threads] '1 (Fig. 4).

formediionythe inner: ends; of the shaftsafit. and

threading into nuts-.12 fixed-.111; the columns: l4. The-leads :ot thevscrews are; such-that theiarms. 6.8:.move toward. each otherat thesamerate-Whentheshaftsrare turned.in-onezdirectiont One arm engages. its work; end before the; other; and shifts a. hydraulic: cylinder 7-3 (-Eigs-=,. 4,,'7 and 18) whose piston; M- has a short. lost. motioneconnection i5. (Fig.1 49 with a. rack ba-r 116;; meshingwith one of two gear segments; '11-. One ofthe-latter is fixed andthe, other splined on a cross-shaft l8, andthe segmentsinturn mesh withpinions it on. the two. screw; shafts. 59.

At the drilling. station. A,. the holes i2. in the opposite; yokesof, the workpiece are; formed. by drills Bil (Fig. 3 guided; in. bushings M which are positioned accurately on the; columns .14: to locate their. axes properly in relation .to the. ends: of: the workyokes l0 and. the axis ofthe workpiece; after final positioning and clamping thereof as de.-. scribed; above. The; drills are carried by-rspindles 82-"..journaled in boxes 83 (Fig, 3):'which are-rigid with slides 8L1 movablein:guideswllit(Figs.v 3. and 45.) formed. inthelfaces of the columns; I 8. Within the: boxes 83 thesspindles carry gears: (not shown): which have spline connectionswith-gears-mounted on the. columnsand driven by; motors 1% (Figs. 1 and,-2), -to.turn.the drillsat the-desired speeds. The, slides; 8.4 are moved toward. and-awayv from each other by. individual hydraulic, actuators. 81- mounted. on the columnsandflhavingpistons con-. nected to, the respective; slides 84.

Except for minor differencesat the inspectingand-boring stations B and D, the elevating, posi-. ticning, locating, and: clam-ping mechanisms abovedescribedare duplicated" at each of the stations A; B, (3,. and D; and. the correspondingparts are indicated. by the; samereference numbers witlrthe addition of the-.lettersof thegresloective stations.

At; the inspecting station. final: positioning. of theiworkpiece: both; vertically. and: sid'ewise. is effected by the Vb.locks :49. (Eig;.12 ),.the secondarty-stops: 5 l5, theclamps fortheV-blocksandthe wedges for further elevating the; rods. 2.8.: being omitteda: Forxthe same. reason, the rack .barsfisarermade rigid withtherrods 23;.as: shown. in Fig. 11 sox'that. the: upward movementaofthe work'- pieces. is determined: by the limitposition'ot the actuating piston 37', the workpieces: having; been brought intoengagement with the; yieldable blocks; 49* at this. time-.-

Provision is made atthestation B to; inspect the parts: of the workpiece". machined at; the. first-stationAfor the'purpose of determiningin this: instance. whether; the holes: i2 ,:hav.ei: been drilled properly throughthe. yokes. Iii; or of;.de-.- tectin-g the presence. of; a. broken driller other obstruction which might render: the. partiallymachined work defective and result .inidamage the piecewcrepermitted-to advance into the next station .or if the previousstation werespermittcdto operate on thenext workpiece. "While such inspection may be effected in various ways, it is accomplished herein by a mechanical feeler in the form of a pin 88 (Figs. 12, 13, and 18) slidable in a guide 89 on the columns I4 and substantially alined with the holes I2 in one end of the workpiece after the latter has been elevated into engagement with the V-block 49 A similar feeler is provided for examining the hobs I2 at the other end of the workpiece.

Intermediate its ends, each pin 88 has a pin and slot connection 90 with one arm of a bell crank 9| fast on a rockshaft 92. The short arm 93 of the bell crank is pivotally connected to the end of a rod 94 on a piston 95 slidable in a cylinder 96 on the column I4. When the piston is retracted to the right as shown in Fig. 12, the pin 88 is withdrawn from the holes I2 of the workpiece then in operating position. Shifting of the piston to the left as shown in Fig. 13 projects the coned end of the pin'through both of the holes I2. In such movement, an arm 91 on the rockshaft 92 engages the follower 93 of a switch L529 thereby indicating that the holes are complete and free of any obstruction. If either hole is obstructed, the pin or feeler will be blocked, and the switch L829 will not be closed, thereby indicating an imperfection in the workpiece. In the return of the pin to its retracted position, a switch L828 is closed.

At the milling station C, the yokes I of the workpiece are each milled internally to form the parallel surfaces I3. This is accomplished by a cutter 99 (Figs. 9 and 21) mounted on a suitable tool head I00 (Fig. 24) and fed through the yoke I0 by a hydraulic actuator IOI, I02.

At the boring station D, the previously drilled holes I2 are finish bored by cutters I03 (Fig. 23) mounted on a common slide I04 (Fig. 14) and moved back and forth by a suitable hydraulic actuator (not shown) so as to bore first one of the holes and then the other. In order to properly position the workpiece angularly at this station, a projection I (Figs. 14, 15 and 23) is made rigid with one of the columns I4 and positioned thereon so as to enter between the previously milled surfaces I3 on one of the yokes as the workpiece is raised into final position. The projection I05 fits snugly in the yoke, and thus holds the latter accurately against turning during operation of the boring tools.

Unloading of the machined workpieces is effected in the manner illustrated in Figs. 16, 17, and 22. A lug I30 is formed on each transfer bar at the inner end of the terminal recesses 22 therein. These lugs are high enough to remain in engagement with the ends of the workpiece being moved out of the boring station D and continue the advance of the piece along with the transfer bars I8 after the workpiece has encountered stationary inclines I3I in the final part of the transfer motion, the workpiece being forced over the top of the inclines I3I and to the posi tion shown in Fig. 17 where it stops with the transfer bars engaging the tubular part II then resting on a downward incline I32. The latter holds the workpiece above the outer ends of the recesses 22 so that the transfer bars may be withdrawn from beneath the piece which is then free to roll down and off from the incline I32.

The extent of the motions produced by the various hydraulic actuators above described may be positively limited by engagement of the pistons with the ends of the respective cylinders or by the provision of stops coacting with the movable parts. All of the actuators are supplied with pressure fluid from one or more sources I05 through the circuits shown in Figs. 24 and 25 which are controlled by so-called four-way valves I81, I08, [09, H0 and III whose movable members are disposed in a neutral position when two associated actuating solenoids are deenergized. When one solenoid is energized, the valve member is shifted to admit pressure fluid to one end of an associated hydraulic cylinder while connecting the other cylinder end to a drain line. When the other valve solenoid is energized, the valve reverses the connections between the cylinder ends and the drain and supply lines.

To cause the movable parts at the different stations to operate in the proper sequence and thereby execute a desired automatic cycle during which successive workpieces are advanced step Operation Assuming that all of the various power actuated parts are in their retracted or idle positions as shown in the circuit diagram (Fig. 24), the cycle of operation proceeds as follows after all of the tool driving motors have been started and pressure fluid is available. Let it further be assumed that a series of workpieces positioned at the stations A, B, C and D have previously been operated on at these stations and are restmg in the recesses 22 of the transfer bars I8 at the respective stations.

When the operator has loaded a rough workpiece into the recesses 22 on the projecting ends of the transfer bars, the cycle may be started by closing a push button switch I I3 (Fig. 1). As a result, a circuit conditioned by closure of various other switches when the parts are positioned as shown is completed to energize a solenoid of the valve I01 for admittin fluid to the head end of the cylinder 23, whereby to advance the transfer bars I8. This motion is terminated in response to closure of a switch LSI3 when the rough workpiece reaches the proper position in the drilling station A. Closure of the latter sw tch completes a circuit for energizing a solehold of the valve I08 to admit fluid to the head end of the cylinder 38 thereby initiating upward movement of the elevator rods 28. The jaws 30 and 3I engage opposite ends of the workpiece and lift the same out of the recesses 22 in the transfer bars.

As the workpiece approaches its u DOSltlOIL determined by the length of 1722 25 3 13 der 38, the yokes I 0 enter in between the then retracted centering arms 68 and thereafter engage 1n the V-shaped sockets 48 of the blocks 49 raising the latter against their springs 50. In the final part of this motion, an arm H4 (Figs. 6 and 24) on the shaft 40 closes a switch LSM which completes a circuit for energizing a solehold of the valve I 09 for introducing pressure fiuid into the head ends of the cylinders 13 at the different stations. The resulting rotation of the shafts 19 moves the equalizing arm 68 toward each other and into engagement with the ends of the workpiece at each station. Each workpiece thus becomes centered. Thereupon, the pressure builds up in the cylinders 13 and at a "proper -value,' closes a switch PS2 for energizing a solenoid-or the valve I H) which directs pressure 'fiuid into the head ends of the cylinders 58 for actuating the wedges 53 at the difierent stations. As the latter advance, the elevator rods 28 are 'cammed upwardly thereby raising the workpiece "against the action-of the spring Elland into abutment with the stops which determine the final vertical position of the workpiece ends. In this movement of the workpiece, the ends of the yokes "It slide along the inner surfaces'of the centering arms 88. V

The valve He also directs pressure fluid into "one endof the cylinder 96 to initiate projection of the feeler 'pin 88 at the'inspecting station E into the previously drilled holes l2 of the workpiece then positioned against the V-blocks 49* at this station. If the holes are free and unblocked, the pin moves freely resulting in closure of a switch LS29 as the piston 95 completes its stroke. If, however, the workpiece is defective and prevents the pin from moving through its "fullstroke, the switch fails to close and prepare a circuit-subsequently used in continuing the machine cycle. As a result, the entire organization is disabled until the defective workpiece has been removed.

Following completion of the strokes of the wedge actuating pistons 55 and the piston 95. at the inspecting station, the pressure of the fluid in the common supply line l [5 through the valve 63 move to turn the shafts 59 and collapse the clamps 65 against opposite sides of the blocks 49 at the stations A and D thereby positively locking the latter to hold the workpieces seated therein "against lateral displacement.

Following such locking, the pressure in the line H5 builds up still further and at a predetermined value closes a pressure switch PS3 which acts in series with the then closed switch L829 to initiate the movements of the metal cutting tools at the stations A, C and D. If by reason of detection of a broken tool or other defect in the workpiece at the inspection station so that the switch L829 is still open, the entire machine cycle will be interrupted automatically before the drills at station A are permitted to engage the next workpiece. Also, the defective workpiece is held against further advance along the line and prevented from causing damage tothe tools or other parts at the succeeding stations.

The combined closure of the switches L829 andPSS deenergizes the active solenoid of the valve Ill! and energizes the other solenoid thereof to reverse the valve so as to direct fluid tolthe cylinder 23 for retracting the transfer bars it. The operator may then load another workpiece while the remainder of the partially executed cycle is being completed.

The same switches L829 and PS3 act conjointly to complete a circuit for energizing the solenoid III for admitting pressure fluid to the cylinders of the tool actuators 87 thereby initiating forward feeding of the drilling tools at the station A. Simultaneously with the energization of the valve III to start feeding of the drills, a

1o valve I l I (Fig/24) is energized'to'initiate feeding of the "milling cutter and asimilar valve (not shown) initiates the-'cycle'of 'theboring head Switches LSB' 'and LSI B are closed when the drilling of the holes 12 "has "been completed therebyrever'sing the valve I11 'toidirect fluid to the actuators ill for retracting the drills to their starting-position (Fig. 3). Completion of this motion closesswitches' Ls'l' and LS8. In 'a similar waya switch :LSB is closedoy ."completion of the" mi'l'l i-ng operation and retraction of the cutter 99' to starting position ands. switch ('notshown) is' c'losed' by completion'of the boring machine cycle Iatistation D. The combined closure :ofall or thesetool responsive switches results in "the eventual renergization of the fiother solenoid of the completion "of "a 'circuit for "-deenergizing thesactivesolenoids or the valves-109 and I10 andenergiz-ing the other sol'enoids thereof. Such reversal 'ofIt-he valve H8 "directs pressure fluid :tothe head'endsof the 'V-block locking cylinders 6'4, the: rod ends "of the wedge actuat- .ing cylinders 58 andthereturn endcf thecy-linderQG at the inspecting station. :As a result, the .feeler pin "88 is retracted out or the workpiece 'at the inspectingstation and thetlainps and wedges atthe stations A, Cand'D are retracted. Reversal'of the va lve Hi9 directs .fiuid to the rod endsof the cylinders 13 causing retraction of the centering arms =68.

With the transfer 'bars l8 fully'retr-acted, 2. switch L'Sldis-closed. Then after full retraction of all of the pistons inthecylinders connected to the line N1, the pressurein the latter builds "up' and clos'esalswitch PSd at a predetermined value. Simultaneously-a predetermined pressure built up in the cylinders 13 after retraction of the centering arms 68 results in clo'sure "of a switch PSI. These :three switches PS-l, PS2:

and L812 act: together to de'energize the active solenoidand eriergize theother solenoid oi" the valve IBE-thereby reversing the latter. This directs fiuid into' the rod end oi 'the cylinders 38 to lower the elevator 'ro ds zt at the different stations. Completion of this motion closes a switch L815 which cooperates with'the transfer bar actuated "switch L312 to prepare a circuit for initiation of the next 'cycle of thema'chines when the starting button M 3 is again depresse'd' by the operator after the starting circuit has been prepared by completion of the necessary motions at the-separate stations.

The various work elevating, centering, locating,

and clamping mechanisms at the inspecting, milling and boring "stations B, 'Cand D and the duplicated mechanisms on the other sides of the line at allci the stati-ons operate simultaneously with the corresponding mechanisms as described above andshown in Figs. 24and 25, the control circuits bein'g paralleled with those already dcscribed. Various interlocks of well known'c'haracter are of course provided for controlling certain of'th'e functionsin order thatthe latter will be executed iii-unison at all of the stations.

In theca-se of the boring operationgone additional function is performedthat' isflenBrgiZation of an actuator I I9 (Fig. 14) for stripping the finished workpiece off from the projection 5615 which enters one yoke IQ of the workpiece at this station to efiect final angular positioning of the piece. This is accomplished by connecting the rod and head ends of a cylinder I20 to the head and rod ends of the elevator cylinder 38 so that a stripper l2l (Figs. 14. and 24) will be 11' raised and lowered with the rods 28 Thus, the stripper follows the rods 28 downwardly and forces the workpiece off from the locater 105 if the yoke l engaged therewith tends to bind and stick to the latter as the rods 28 are lowered.

I claim as my invention:

1. In a machine tool, the combination of, a pair of laterally spaced bars supported for horizontal reciprocation back and forth and in unison with each other, means formed on and spaced along said bars and interengageable with the opposite end portions of a series of workpieces to support the latter in uniformly spaced relation and hold the pieces against sidewise shifting relative to the bars, power actuated mechanism operable to move said bars back and forth and carry successive workpieces resting thereon into a predetermined position; abutments disposed above and facing downwardly toward said bars for engagement with a workpiece at said position, elevators engageable with the opposite end portions of the workpiece in said position and movable upwardly to carry the workpiece against said abutments, means engageable with opposite end portions of the elevated workpiece and operable during the approach thereof to said abutments to center the workpiece sidewise, separate means engageable with opposite end portions of the located workpiece and movable to center the latter endwise, and means for clamping the workpiece after location and centering thereof sidewise and endwise.

2. In a machine tool, the combination of a work supporting member engageable with a series of uniformly spaced parallel workpieces to support the latter, power actuated mechanism operable to move said member back and forth and carry successive workpieces into a predetermined position, vertically yieldable V-shaped abutments disposed above and facing downwardly toward said member for engagement with a workpiece raised from said position, fixed abutments disposed above said yieldable abutments and facing downwardly for engagement with spaced portions of a workpiece disposed against the yieldable abutments, elevators engageable with spaced portions of the workpiece in said position and movable upwardly to carry the workpiece against said yieldable abutments, means engageable with opposite end portions of the located workpiece and movable to shift the same along said yieldable abutments and center the piece endwise, means for raising said elevators further to overcome said yieldable abutments and carry the workpiece against said fixed abutments, and means for clamping said yieldable abutments against movement. v

3. In a machine tool, the combination of a transfer element engageable with a series of uniformly spaced workpieces, power actuated mechanism operable to move said element to carry successive workpieces into a predetermined position, a yieldable forked abutment spaced from and facing toward said element for engagement with a workpiece shifted from said position, a fixed abutment positioned for engagement with a workpiece disposed against the yieldable abutin said position and movable to carry the workpiece against said yieldable abutment and into the fork thereof whereby to center the workpiece in one direction, means engageable with the located workpiece and movable to shift the same along said yieldable abutment to a predetermined position and center the piece in a transverse direction, and means for further moving said members to overcome said yieldable abutment and carry the workpiece against said fixed abutment.

4. In a machine tool, the combination of a work supporting member engageable with a series of uniformly spaced parallel workpieces to support the latter from said member, power actuated mechanism operable to move said member back and forth and carry successive workpieces into a predetermined position, vertically yieldable forked abutments disposed above and facing downwardly toward said member for engagement with a workpiece raised from said position, fixed abutments disposed above said yieldable abutments and facing downwardly for engagement with spaced portions of a workpiece disposed against the yieldable abutments, elevators engageable with spaced portions of the workpiece in said position and movable upwardly to carry the workpiece first against said yieldable abutments and then further into engagement with said fixed abutments, and power actuated means for actuating said elevators after location of the workpiece against said abutments to clamp the workpiece firmly against the latter.

5. In a machine tool, the combination of a work supporting member engageable with a series of uniformly spaced parallel workpieces to support the latter, power actuated mechanism operable to move said member back and forth and carry successive workpieces into a predetermined position, fixed abutments disposed above and facing downwardly toward said member for engagement with a workpiece when the latter is raised from said position, elevator engageable with spaced portions of the workpiece in said position and movable upwardly to raise the piece to a position short of said abutments, means acting on spaced portions of the workpiece during raising thereof to locate the workpiece horizontally in one direction, elements disposed at the ends of the workpiece and movable toward each other after raising of the workpiece and location thereof in said one direction to center the latter in a transverse horizontal direction, and means for further raising said elevators to clamp the workpiece against said abutments.

EARL M. BOWEN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,794,143 Broecker Feb. 24, 1931 2,103,147 Cole Dec. 21, 1937 2,193,840 Oberhoffken et al. Mar. 19,1940 2,238,921 Waldsmith Apr. 22, 1941 2,302,878 Muhl et al. Nov. 24, 1942 

